Shelter life raft



June 5', 1962 J. D. BROOKS m 3,037,218

SHELTER LIFE RAFT 3 Sheets-Sheet 1 Filed July 11, 1960 INVENTOR.

Jefferson 0. Brooks 1111 ATTORNEY June 5, 1962 J. D. BROOKS m 3,037,218

SHELTER LIFE RAFT Filed July 11, 1960 s Sheets-Sheet 2 INVENTOR.

Jefferson 0. Broo/rsm A TTOR/VEY June 5, 1962 J. D. BROOKS m 3,037,218

SHELTER LIFE RAFT Filed July 11, 1960 3 Sheets-Sheet 3 INVENTOR; fferson D. Brooks 1:;

ATTORNEY Unite 3,037,218 Patented June 5,1962

3,637,218 SHELTER LKFE RAFT Jefferson D. Brooks III, Raleigh, N.C., assignor to National Textile Research, Inc, Raleigh, N.C., a corporation of North Carolina Filed July 11, 1960, Ser. No. 41,911 7 Claims. (Cl. 9-11) This invention relates to an inflatable structure for emergency use as an enclosed life raft or land shelter.

The art of inflatable structures designed for use either as a life raft or shelter has recognized the need for a self erecting, inflatable enclosure which offers both buoyancy and weather protection as a lift raft and weather protection as a land shelter and which can be packaged for free fall delivery from aircraft and the like. The self erecting and enclosure features are desirable to relieve survivors of the burden of having to erect canopy walls and to provide immediate protection from the weather or sea. The art has also recognized the need for inflatable structures which are invertible, that is, which have some serviceability irrespective of which side of the raft is up and which include two independently inflatable flotation tubes mounted one on the other. Invertible type rafts relieve survivors of the task of having to put the raft in a right side up position and in the event of damage to the active buoyancy tube, the raft may be inverted so that the damaged tube can be repaired while the other tube is being used for buoyancy. This is a highly desirable feature to avoid dependence on one flotation tube. However, such rafts have relatively low freeboard and to accomplish repairs the survivors are required to enter the water While inverting the raft. So far as is known, the art has not as yet provided an inflatable structure for free fall delivery Without use of a parachute, which has both the self erecting and enclosure features, which as a life raft is invertible and can be used and easily boarded in either of two upright positions, which has high freeboard, which can be inverted in water by its occupants while remaining inside the structure and which provides two independently inflatable flotation members.

An object of the present invention is, therefore, to provide an inflatable structure wfu'ch is adaptable for free fall delivery from aircraft, ships and the like and which is useful for both enclosed life raft and land shelter purposes, which is self erecting, which is invertible and which can be inverted in water without requiring the survivors to enter the water.

Another object is to provide an inflatable structure which can be thrown in free fall delivery and which, upon being inflated and irrespective of its landing position, immediately provides an enclosed, erect structure suitable for use as a land shelter or enclosed life raft.

Another object is to provide an inflatable, erect, ready to use shelter life raft type structure whose structural shelter support and buoyancy characteristics can be maintained by either of two independently inflatable tube systems.

Another object is to provide an invertible inflatable shelter life raft structure having two independently inflatable buoyancy tubes, one for active and one for auxiliary buoyancy, and in which the auxiliary buoyancy tube is supported substantially above the active buoyancy tube in order that the auxiliary buoyancy tube, while in such position, may be used as a canopy support and provide headroom between the two tubes.

Another object is to provide an improved entryway for the sidewall of an inflatable shelter life raft structure wherein the relatively high freeboard of the structure at that entryway may be maintained irrespective of whether the entryway is in one uprightposition or another.

Another object is to provide an improved entryway for the sidewall of an inflatable shelter life raft structure wherein the entry way includes a novel inflatable hinged boarding ramp which may act as a boarding ramp in open position and as a bulkhead in closed position.

Another object is to provide an inflatable shelter life raft structure having improved means for collecting and storing rain Water.

Other and further objects will appear as the description proceeds and in the drawings, in which:

FIGURE 1 represents a somewhat schematic perspective drawing of an inflated tube and column structure embodying the invention;

FIGURE 2 represents a perspective view of an enclosed structure embodying the tube and column structure of FIGURE 1 and showing one of the entryways in closed position;

FIGURE 3 is an enlarged vertical sectional view taken on line 3-3 of FIGURE 2;

FIGURE 4 is an enlarged view of one of the entryways showing the door in down position;

FIGURE 5 is a view of one form of pattern by which the material used for the inside and outside entryway gussets may be cut;

FIGURE 6 is an enlarged horizontal sectional view taken along line 66 of FIGURE 4;

FIGURE 7 is an enlargement showing how the mast post is attached to the floor;

FIGURE 8 is a somewhat schematic view showing the general arrangement of the entryways;

FIGURE 9 is a plan view of an alternative type of partially inflated floor; and

FIGURE 10 is an enlargement of the vertical section taken along lines 10-10 of FIGURE 9.

Referring to the drawings there is shown in FIGURE 1 'an inflatable tube structure embodying the invention and composed of various air retaining fabric members. One of the important features of the invention is that the inflated members give both structural support for shelter purposes and buoyancy for raft purposes and this support and buoyancy is obtainable irrespective of the position of the structure on landing and irrespective of whether all of the members are inflated. The tube structure of FIG- URE 1 in illustration of this feature includes a circumferentially disposed inflatable tube 10 inflated by a valve 11 and on top of which are fixedly mounted at intervals around the tube periphery a plurality of vertically disposed inflatable tubular columns 12. Each of the columns 12 are closed at their upper ends 13 but are placed in air communication at their lower ends 14 with tube 10 through orifices 15. That is, when tube 10 is inflated, columns 12 are also inflated by reason of being in air communication with tube 10.

Located opposite and vertically spaced above circumferentially disposed tube 10 and preferably of identical shape and size is a second circumferential tube 16 having a valve 17 located opposite valve 11. Extending downwardly from tube 10 are a plurality of vertically disposed columns 18 each of which is closed at its lower end 19 but at its upper end 20 is in air communication with tube 16 through orifices 21. With this arrangement, when tube 16 is inflated, columns 18 are also inflated by reason of the air communication between the tube and columns. If desired, columns 12 as well as columns 18 may, of course, each be individually inflatable.

Columns 12 and 18 are preferably formed by means well known in the inflated fabric art with their ends somewhat convex as shown in FIGURE 2 to facilitate joining the columns to the tubes 10 and 16. In a preferred method of manufacture, each set of columns together with its re spective circumferential 'tube is fabricated and the columns are sealed to the tube by conventional tape means.

Following this, the closed ends of the columns are sealed to the opposite tube. That is, the closed ends 19 of columns 18 are joined to tube after the ends have been joined to tube 16 and in a similar manner, the ends of columns 12 are joined to both tube 10 and tube 16. However, columns 18 are only in air communication with tube 16 and columns 12 are only in air communication with tube 10. Once assembled, the tubes and columns form an integral, symmetrical inflatable structure in which the columns rest on one tube and support the tube opposite. While the tube periphery of tubes 10 and 16 is shown in polygonal form, tubes 10 and 16 could be in a circular, square or other periphery shape. They should, however, be of the same shape and size to fully realize the advantages of the invention.

With the separate tube-column air chambers described, it can be seen that neither buoyancy nor structural support is dependent on just one of the tube-column systems since both buoyancy and structural support are obtainable even though one of the tube-column systems is completely deflated. For example, if tube 10 and columns 12 are deflated as by damage, the structure may be inverted and tube 16 and columns '18 used for both buoyancy and structural support. 'Ihose familiar with the invertible raft art and the conventional practice of mounting the auxiliary tube directly on top of the active tube will recognize the advantage of elevating the auxiliary buoyancy tube substantially above the active flotation tube in that the auxiliary tube in elevated position may provide a type of inflatable structural support for canopy purposes and for headroom between the active and auxiliary tubes which advantages are not realized with the conventional invertible system of tubes.

FIGURE 2 shows the inflatable structure of the invention as it appears in fully inflated condition ready for occupancy as either a sheltered life raft or land shelter. To complete the basic buoyancy structure described in connection with FIGURE 1, a waterproof fabric cover 21 is sealed by conventional tape means to and across tube 16, preferably along its uppermost surface, and a similar waterproof fabric cover 22 (FIGURE 3) is sealed to tube 10, preferably along its lowermost surface. Sealed to the outermost side surface of tubes 10 and 16 is a vertical waterproof fabric Wall 23 equipped with suitable windows 24 and which extends completely around the raft with the exception of interruptions for entryways as later explained. For the purpose of giving the raft a resistance to overturning, appropriate sized Water ballasts 25 having open ports 26 are attached to tubes 10 and 16 as indicated, the size, number and location of the ballasts being varied to suit the specific size raft. When used as a land shelter, ballast 25 may be filled with dirt, rock and the like to assist in resisting wind pressure against the structure.

Inflation of the column and tube structure of FIGURE 1 is accomplished by means of oppositely disposed carbon dioxide cylinders 27 and 28, cylinder 27 being used to inflate tube 10 and air connected columns 12 and cylinder 28 being used to separately inflate tube 16 and air connected columns 18. Other forms of air or gas storage cylinders may be adapted and used for the same purpose and where desired, may be equipped with manually operated valves or for automatic inflation by ripcord or by impact with water or land. Once inflated, it can be seen that an erect, enclosed structure is immediately made available to survivors.

A principal feature of the invention resides in the entryway construction wherein entry can be easily gained irrespective of the position of landing and wherein the freeboard of the raft may be maintained at the same height irrespective of the rafts position. By freeboard is meant the height above water of the nearest opening which will admit water into the raft. The entryway construction of the invention provides for ease of boarding and this entryway and door system is illustrated in FIG- URES 2, 3, 4 and 8. The system consists of a pair of doors 29, 30 preferably formed of a two ply inflatable fabric, including, using door 29 as an example in FIG- URE 3, inner and outer plies 31, 32 sealed around their edges as illustrated at 33, in FIGURE 4. Attached to the outer plies 32 are separate sources of manually operated inflation 34, 35 for doors 29 and 30 respectively. In closed position as dropped for delivery, the doors are held in place by snap fasteners having matching components 36 and 36 attached, respectively, to the inner surface of the door and outer surface of the tube.

As being representative of the construction used in doors 29 and 3%, door 29 is shown in FIGURE 2 as it appears in closed position and in FIGURES 3 and 4 as it appears in open position. The line of sealing indicated at 37 between door 29 and tube 10 acts as a hinge such that door 29 is enabled to swing outwardly and downwardly from the closed position indicated in FIGURE 2. Sealed to the side edges of door 29 and to the vertical edges of the entryway in fabric wall 23 at which door 29 is located are a pair of gussets 38, 39 equipped with drawstrings 40, 41. Assuming the raft lands in the position shown in FIGURE 2, the survivors would maneuver the raft until they are in front of door 29, would next inflate door 29 by manually operating cylinder 34 and would next lower the door by unfastening fasteners 36. This would place the door in the boarding position shown in FIGURE 4. After boarding, drawstrings 40, 41 would be drawn which would then restore door 29 to its bulkhead position shown in FIGURE 2. That is, door 29 serves as a boarding ramp when open and as a bulkhead when closed. So far as door 29 is concerned, it can be seen that the freeboard at this door is maintained at the height of the drawn gussets 38, 39 since with the gussets drawn, water could not enter without going over the top of the gussets. To make the entryway at door 29 invertible, that is, capable of preventing entry of water irrespective of its particular vertical position, there is provided within the raft an inner door in the form of a flap 42 hinged along a line of sealing 43. Sealed to the side edges of flap 42 are a pair of gussets 44, 45 which are preferably a continuation of and similar to the gussets 38, 39. Gussets 44, 45 are equipped with drawstrings 46, 47. Before dropping the raft for delivery, flap 42 may be raised and fastened with snap fasteners 48 as indicated in FIGURE 3 or lowered and its gussets 44, 45 drawn as shown in FIGURE 4. When the raft is inverted from the position of FIGURE 2, it can be seen that, essentially the same freeboard at door 29 can be maintained by drawing gussets 44, 45 since in the second position, the water would have to go over the drawn gussets 44, 45 in order to enter the raft. Gussets 38, 39 when drawn, thus act at this entryway to maintain the freeboard in one position and gussets 44, 45 act to maintain the freeboard in the opposite position.

In practice the inside and outside gussets attached to the inner door flap 42 and the outside door 29 respectively may be made of one continuous piece of waterproof fabric material cut generally in the shape indicated in FIGURE 5 in which gussets 38 and 44 are used as examples of the general construction. Assuming that the piece of fabric material represented in FIGURE 5 is to be used to make outside gussets 38 and inside gusset 44, the material would be cut in the shape indicated and would be sealed to inside flap 42 along edge 49 and would be sealed to outside door 29 along edge 50. Additionally, the gusset material would be sealed to tube 16 along the curved edge 51 and would be sealed to tube 10 along the curved edge 52. Further, a line of waterproof sealing between the outer wall fabric 23 and the gusset material would be made generally along the reference line 53. This may be accomplished as shown in FIGURE 6 by applying a so called V-tape, a sealing tape, to the junction of the outer wall fabric and the gusset.

FIGURE 6 illustrates the joining of gusset 45 and 39 to wall 23 by means of V-tape 54 to show the construction. Such general and well known mode of sealing construction is followed around both entryways to make them waterproof at the junction of the wall 23 and the gussets.

Looking especially at FIGURE 3, it will be seen that opposite the entryway construction which includes door 29 and flap 42 there is located a similar door 30. Door 30 is hinged however at a line of sealing 55 so as to swing upwardly with respect to door 29, the arrows indicating the directions in which the doors move when going to open positions. That is, when the raft is inverted from the position of FIGURE 2, door 30 will be able to assume the same position as door 29 has in FIGURE 4. An inner door flap 56 hinged at a line of sealing 57 is provided so as to operate oppositely with respect to flap 42. That is, flap 56 in opening moves down to the dotted line position 56' whereas flap 42 in respect to flap 56 moves up to open. Flap 56 may be retained in open position by means of snap fasteners indicated at 58. The general construction adopted for door 29 and flap 42 and their associated gussets 38, 39, 44 and 45 is followed in respect to door 30 and flap 56 in that door 30 and flap 56 are equipped with a similar arrangement of gussets, not shown in detail.

As further illustrated in FIGURE 8, the entryway arrangement provides one hinged outside door that, in opening, swings upwardly and outwardly and another hinged outside door that, in opening, swings downwardly and outwardly with respect to the first. The invention also provides at each such outside door a hinged inner door flap which swings oppositely from the door to which it is adjacent and both the flaps and the doors are provided with attached gussets which, when drawn, are of substantially the same. height. For purposes of illustra: tion, all of the doors are shown open in FIGURE 8 and the arrows indicate the directions in which the doors move to close. This arrangement insures that the raft will always have at least one entryway avail-able with a horizontally positionable, gusset supported, door for boarding purposes and also makes utility of the raft independent of raft position. A high freeboard is preserved independent of position since at each entryway there is always, in either vertical position of the raft, either an outer or inner gusseted door which may be drawn to serve as a water barrier or bulkhead at that entryway. Because of the high freeboard character istic, the raft is unsinkable solely from loading of survivors, since maximum occupancy by survivors cannot exceed the water displacement.

An advantage of the inventions construction resides in its water collecting ability due to the relatively large flat surface which is always exposed to rain. Water collects on covers 21 or 22, depending on which is in the upper position, and to preserve such water, there is provided of water-proof fabric a hollow, inflatable, tubular mast 59 having at its closed ends manually operable valves 60, 61 which may be connected through a tube 62 to similar valves 63, 64 located respectively in covers 21 and 22. Valves 60, 61 and 63, 64 are known as MK flush type topping off valves, one manufacturer being Pam Air Products Company, Palisades Park, New Jersey. The valves have a threaded top, not shown in detail, which is rotated in a counter-clockwise direction to open the vent in the valve whereupon air or liquids may pass through the valve. When sufiicient air or liquid has passed, the valve vent is closed by rotating the top in the opposite direction. With the raft in the position of FIGURE 3, with valves 61, 64 closed, with valves 60, 63 open and with tube 62 connected between valves 63 and 60, water may flow into mast 59 and there collect. After collecting the desired amount, tube 62 may be disconnected and valve 63 closed. Valve 60 may be partially closed for gravity flow from valve 61 or, if desired, air pressure 6 may be introduced by blowing through tube 62 while connected to valve 60 and then closing valve 60 after which Water would be available under pressure at valve 61. The mast would also act as a support.

As representing the manner of positioning the mast on the covers, there is shown in FIGURE 7 a set of straps 65 permanently attached at one end to mast 59 and equipped at the other end with snap fasteners 66 by which the straps may be removably connected to the cover 21, a similar arrangement being adopted for cover 22.

For minimum weight and cost covers 21, 22 and side Wall fabric 23 should preferably be of suitable single ply fabric. However, such covers and side wall may be constructed of the Well known two ply inflatable fabric and be separately inflatable so as to enhance the safety, in sulating, buoyancy and supporting properties of the covers and side wall. Columns 12 and 18 may, for example, be replaced by an inflated side wall running around the periphery of the raft between the active and auxiliary tubes and with sufficient rigidity to act in the manner of columns 12 and 18.

An alternative means of introducing some additional buoyancy and additional insulation in the covers and also for providing a means to lift the structure off the ground when used as a land shelter, is shown in FIGURES 9 and 10. In these figures, 67, 68 represent annular pieces of suitable fabric material which have been scaled to floor 21, as an example, by means of sealing V tape 69 as generally indicated in FIGURE 10. Once in position and sealed, rings 67 and 68 together with that portion of the fabric of floor 21 included between the sealed edges of the rings, forms a type of inflatable, circumferential, tubular structure which, by means of manually operated valves 70, 71, may be inflated from within the raft. By using the floor fabric as a substantial part of the crosssectional periphery of the tubular structure, considerable savings in material are achieved while at the same time, additional buoyancy and insulation are achieved.

Prior to use, the raft may be packed for aerial free faill delivery or for throwing overboard in shipboard use. Doors 29, 30 should preferably be placed in closed position and flaps 42, 56 in open position during packaging. With the raft floating in inflated condition on the sea, the survovors, by means of hand lines 72, may rotate the raft until they face the particular outside entryway door that has fallen to an upright position, After inflating this particular outside door and unfastening it from its closed 'position, the survivors will have available a buoyant, gusset supported, boarding surface and with the inside fiap previously packaged in raised position, the survivors will have a clear entry into the raft. After boarding the raft and drawing the various gussets to establish a high freeboard, ventilation may be achieved, depending on weather conditions, by controlling the amount by which the gussets are tightened so as to control the amount of opening around the doors. To supplement this form of ventilation, there are provided conventional adjustable ventilator-s 73 located in windows 24 midway of the height of side wall 23.

Assuming the raft lands and is inflated in the position indicated in FIGURE 2 and is boarded by the survivors in such position, damage may be incurred which would require that tube 10 be temporarily relieved of the buoyancy load. In such event, the survivors may shift their weight to one location, preferably at points P-1 or P-2 indicated in FIGURE 2, and with all of the survivors weight at this point and with a slight rocking motion by the survivors, the raft may be completely overturned so as to place the buoyancy load on tube 16 and make tube 10 available for repairs. In carrying out this procedure of overturning the raft and in making the actual repairs either within or on top of the raft, the survivors are spared the necessity of entering the water.

Irrespective of the possible deflation of one of the tubes and its air connected columns such as tube 10 and 7 columns 12, both the buoyancy and the structural support may be maintained through the other tube and its air connected columns such as tube 16 and its columns 18.

Having described my invention, I claim:

1. An invertible entryway for a vertically disposed sidewall in an inflatable structure having inflatable vertically spaced and horizontally disposed top and bottom tubes between which said side wall is connected comprising, an outside door extending between said tubes and hingedly connected to said bottom tube; outside gussets sealed on each side of said entryway to said side wall and to the respective side edges of said outside door; an inside door extending between said tubes and hingedly connected to said top tube; inside gussets sealed on each side of said entryway to said side wall and the respective side edges of said inside door; means to draw said gussets closed whereby when said structure resides on said bottom tube, the freeboard thereof is established by said outside gussets and when said structure resides on said top tube, the freeboard thereof is established by said inside gussets.

2. An invertible entryway as claimed in claim 1 in which said outside door is made inflatable.

3. In an inflatable shelter life raft having upper and lower horizontally disposed canopy covers, an improved water collecting mast comprising a vertically disposed, hollow, inflatable, tubular, closed structure extending between said covers; fastening means for holding said mast in position with respect to said covers; valve means at the upper and lower ends of said structure; additional valve means in said covers; tube means whereby said cover valve means may pass water to said valve means in said structure whereby water collecting on the upper of said covers may be directed into the upper end of said mast and whereby inflation of said mast acts to simultaneously support said upper on said lower cover and place pressure above said water.

4. In an inflatable life raft of the type having a pair of substantially identical, circumferentially disposed, separately inflatable, flotation tubes for active and auxiliary flotation purposes, the improvement comprising: vertically disposed, inflatable means fixedly mounted to and between said tubes wherein the auxiliary tube is always fixedly positioned above the active tube thereby providing headroom between said tubes; floor means connected to and extending across each of said tubes; vertically disposed wall means connected to and extending around the sides of said tubes; closable entryways located in said wall means, said closable entryways including at each entryway an outer door hingedly connected to one of said tubes and an inner door hingedly connected to the other of said tubes and adjustable gusset means connected to the edges of each of. said doors and to said vertically disposed wall means whereby the freeboard at each entryway may be maintained at a given height irrespective of which of said tubes is in active flotation; said improvement thereby providing an inflatable, self-supporting, enclosed structure having equal serviceability with either of said tubes in active flotation.

5. An inflatable shelter life raft comprising a first circumferentially disposed inflatable flotation and base tube; a plurality of inflatable vertical columns of uniform size and length fixedly mounted on and above said first tube; a second circumferentially disposed inflatable flotation and base tube fixedly mounted on said columns above said first tube, said tubes being symmetrical in shape and size; floors connected to and mounted across each of said tubes; a side wall connected to and extending between and around said tubes and including a pair of oppositely disposed closable entryways comprising at one entryway a gusseted outside door hingedly connected to said first tube and an adjacent gusseted inside door hingedly connected to said second tube and at the other entryway, a gusseted outside door hingedly connected to said second tube and an adjacent gusseted inside door hingedly connected to said first tube whereby the freeboard of said raft may be maintained at a uniform height with either of said tubes in flotation and base position, whereby to provide an invertible self-supporting, enclosed and inflatable structure having equal serviceability with either of said tubes in flotation and base position.

6. An inflatable shelter life raft as claimed in claim 5 in which said outside doors are made individually inflatable.

7. An inflatable shelter lift raft as claimed in claim 5 in which alternate ones of said columns are inflatable with said first tube and intermediate ones of said columns are inflatable with said second tube.

References Cited in the file of this patent UNITED STATES PATENTS 2,752,616 Coates et a1. July 3, 1956 FOREIGN PATENTS 1,074,765 France Apr. 7, 1954 1,127,913 France Aug, 20, 1956 1,181,880 France Jan. 12, 1959 

